I’m trying to create my first block, but I encountered some issues.

Should this be a functioning guide on how to create a custom block? I'm trying to make my first one just to test it, but with these instructions, the block doesn't appear in the block editor.

I followed these simple instructions:

https://lpagery.io/tutorial/how-to-create-a-custom-wordpress-block-without-plugins-in-4-easy-steps-2024/